1. Field of the Invention
The present invention relates to a figure displaying device for displaying dot information in a raster scan television on the basis of the data fed out of a computer, and more particularly to a visual scene display to be attached to a simulator for pilot training by computer generated imagery (CGI) technology.
2. Description of the Prior Art
In a color visual scene display according to the prior art, in case the information fed out of a computer is displayed in a raster scan television, the so-called "frame memory system," in which there is provided a frame memory having a capacity of (the whole number of picture elements).times.(the number of available colors), has heretofore been used because there is a time limit in constructing the screen of the raster scan television. However, the frame memory system has a drawback in that the memory capacity is increased to a remarkable level as the resolution of the screen is improved and as the number of available colors is increased. In case, moreover, such dynamic scenes as have their frames changed each 33 milli-seconds are to be displayed, the writing and reading operations are alternately repeated such that the information from the computer is being written in one frame memory while the previous written information is read out of another frame memory so that it is displayed. As a result, it becomes necessary to provide two sets of the aforementioned frame memories. This provision is accompanied by the further increase in the memory capacity.
In the simulator for pilot training, for instance, it is important that light points are displayed to simulate the night flights. The use of the aforementioned frame memory system with a view to displaying such dot information is markedly uneconomical.